Required practicals

• Investigating energy transfers

  1)Pour boiled water in sealable container

  2) Measure initial temperature with thermometer

  3)Seal container and leave for 5 minutes, use stopwatch

  4) Remove seal and measure final temperature

  5) Repeat experiment but with seals with different matierials
• Investigating wire length on resistance practical

  1)Attach crocodile clip to wire, level to 0cm on ruler

  2)Attach 2nd croc. clip to to wire 10cm away from 1st clip, note length between wires

  3)Close switch then record current with ammeter and pd with voltmeter

  4)Open switch and move 2nd croc. clip 10cm along, close switch and record new length, current and p.d

  5)Repeat and plot graph with results
• Where shall the ammeter be placed?

  In series
• Where shall the voltmeter be placed?

  in parallel
• I-V characteristics practical

  1)Set up circuit of battery, variable resistor, a component, ammeter in series and a voltmeter in parallel

  2)Begin to vary variable resistor which alters flow of current and p.d

  3)Take reading from ammeter and voltmeter and repeat each reading twice

  4)Swap over wires connected to battery, so direction of current is reversed

  5)Plot graph with recorded results
• What component does this I-V graph represent?

  Ohmic Conductor

  
• What component does this I-V graph represent?

  Filament Lamp

  
• What component does this I-V graph represent?

  Diode

  
• Describe the relationship between current, resistance and p.d in this I-V graph of an Ohmic Conductor

  Current is directly proportionate to potential difference resulting in the straight line

  
• Describe the relationship between current, resistance and p.d in this I-V graph of a Filament lamp

  As current increases, the temperature of the filament lamp increases, so resistance increases meaning less current can flow resulting in the graph being shallower

  
• Describe the relationship between current and resistance in this I-V graph of a diode


  Current only flows in ONE direction through a diode, there is a very high resistance in the reverse direction

  
• Investigating effect of resistors in series

  1)Build circuit with a resistor, battery and ammeter and note p.d of battery, measure current with ammeter

  2)Add another resistor in series with the first and measure current and use p.d to calculate resistance

  3)Repeat by adding resistors and calculating current
• Investigating effect of resistors in parallel

  1)Build circuit with resistor, battery and ammeter in series and measure current with ammeter

  2) Add another resistor in parallel and measure total current and use p.d of battery calculate resistance

  3)Repeat by adding resistors in parallel

  4)Plot graph using current x p.d calculations
• Adding resistors in series INCREASES total resistance of the circuit decreasing the total current
• Adding resistors in parallel increases current which decreases resistance
• To find the density of a Solid object

  1)Use a balance to measure its mass, then work out its volume

  2)For a trickier shaped solid, fill a eureka can with water that's level to the spout

  3) Place the object in and collect the displaced water in a measuring cylinder and the displaced water is the volume of the object

  3)Use the D=M/V formula to find its density
• To find the density of a liquid

  1)Place measuring cylinder on a scale and zero it out

  2)Pour 10ml of the liquid into cylinder and record its mass

  3)Pour another 10ml and record the total volume and mass

  4)Repeat until cylinder is full

  5) Use D=M/V equation to find density
• Zero error is when the apparatus doesn't read zero 100% of the time
• An experiment is not reproducible if two trials cannot produce the same result
• A systematic error is an unpredictable error that changes one measurement to another
• Accuracy is being close to the true value, precision is when all your values obtained are close
• Specific heat capacity

  1. Measure the mass of the metal block using a balance
  2. Insert the immersion heater and thermometer into the blocks holes
  3. Record the initial temperature of the block
  4. Insulate the block with a insulating material to minimise heat loss
  5. Set up a circuit with the heater, power supply and ammeter
  6. After turning on the heater record the highest temperature reached
  7. Use the specific heat capacity formula
• During the specific heat capacity practical, when you turn on the power, the current does work on the heater transferring energy electrically to its thermal energy store which causes the materials temperature to increase
• Sources of inaccuracy for shc practical

  • Thermal energy passing out of the beaker - use a insulator with a low thermal conductivity
  • Not all thermal energy from the immersion heater passing into the oil
  • Incorrect reading of the thermometer